Method of making an elongated hollow concrete body



y 3, 1966 H. c. GEORGH 3,249,664

METHOD OF MAKING AN ELONGATED HOLLOW CONCRETE BODY Filed Dec. 15, 1962 2 Sheets-Sheet 1 H. C. GEORGll May 3, 1966 METHOD OF MAKING AN ELONGATED HOLLOW CONCRETE BODY 2 Sheets-Sheet 2 Filed Dec. 13, 1962 United States Patent Ofi ice I Patented May 3, 1966 3 249,664 METHOD OF MAKING: AN ELONGATED HOLLOW CONCRETE BODY Hans Christer Georgii, 42 Rindogatan, Stockholm, Swede Filed Dec. 13, 1962, Ser. No. 245,354

Claims priority, application Sweden, Dec. 21, 1961,

6 Claims. (Cl. 264-88) 'has been launched. This method requires, however, available and suitable fabricating sites of considerable area for the pouring of the concrete bodyand a considerable amount of complicated work and equipment for the launching of the fabricated concrete body, which normally is of very large dimensions.

It is also 'known to fabricate elongated hollow concrete bodies for quay constructions and similar objects directly in the water by means of forms floating on the water surface. According to this method the progressive fabrication of the concrete body is carried outin horizontal direction, ie the already fabricated portion of the concrete body is floating in the water with its longitudinal axis horizontal and with one. or several floating forms connected to one or both ends of the already fabricated portion .of the concrete body. These forms are filled with concrete for the continued fabrication of the concrete body and support the last fabricated portion of the concrete body, until the concrete in this 'portion has set and obtained sufficient strength. Thereafter the form is removed from the already fabricated portion of the is a comparatively complicated and time-consuming operation.

It is also known to fabricate concrete caissons, which are to be lowered into a water-bed and which are not too high, directly at the place, where the caisson is to be the upper, last poured portion of the caisson and the form.

Due to this the method can be used only for caissons having a comparatively short length in the vertical direction. Further, rather complicated devices are required 6 for the lowering of the caisson relative to the pontoons, while the weight of the caisson is simultaneously supported from the pontoons. Further the method is sensitive to currents and wave-motions in the water as these will cause practically unavoidable relative movementsbetween the form supported from the pontoons and the upper, last fabricated portion of the caisson, which has not yet completely set.

Oneof the objects of the invention is to provide a method for fabricating an elongated hollow concrete body of considerable length, for instance several hundred feet.

Another object is to provide a method for fabricating an elongated hollow concrete body by progressive pours of concrete in vertical direction from one end of the body towards the other end, while lowering the already fabricated portion of the concrete body into water.

Another object of the invention is to provide a method for fabricating an elongated hollow concrete body, whereby the body may be fabricated in water at one place and thereafter floated to another place, where the concrete body is to be used.

Another object of the invention is to provide a method of fabricating an elongated hollow concrete body in water, which method does not require any pontoons, tanks, barges or similar equipment for supporting the weight of the already fabricated portion of the concrete body during the fabrication process.

Still another object of the invention is to provide a method for fabricating an elongated hollow concrete body in water, where the method is insensitive to currents and wave-motions in the water. 7

The novel method provided by the present invention for making an elongated hollow concrete body comprises the steps of fabricating first a comparatively short end section for the hollow concrete body, having one end closed and the opposite end open; placing the closed end sec tion with its axis vertical and the open end facing upwards on the surface of a body of water so that the end section is floating substantially independently in the water with its upper edge above the surface of said water and its entire weight balanced by the upward thrust of the surrounding water; placing a form for the pouring of concrete along the upper edge of the end section; progressively fabricating the concrete body on top of the upper edge of said end section vertically upwards, by pouring concrete in the form and progressively raising the form vertically upwards relativeto the fabricated portion of the concrete body; and simultaneously filling Water into the end section of and the fabricated portion of the concrete body so that said end section and said fabricated portion of the concrete body sink together vertically downwards in the surrounding water but are outrapidly and in a simple way by means of conventional techniques and forms.

In a preferred embodiment of the invention the form for the pouring of the concrete is entirely supported from the end section or the already fabricated portion of the concrete body. Preferably the slip-form technique is used for the pouring of the concrete, the slip-form being supported on the upper edge of the fabricated portion of the concrete body and being progressively elevated as the pouring of the concrete proceeds and the concrete sets.

As in the method according to the invention the already fabricated portion of the concrete body is independently floating in the surrounding water and has its entire weight balanced by the upward thrust from the Water during the entire fabrication process, the method does not require any complicated and expensive pontoon equipment for supporting the weight of the concrete body. Because of this, concrete bodies having a very large length, e.g. several hundred feet and-more, can be fabricated by the method according to the invention.

As no relative movements can appear between the concrete body and the form, when the method according to the invention is used, currents and wave-motions in the surrounding water cannot cause disturbances. Further, the water filled into the already fabricated portion of the concrete body during the fabrication process will partially counteract the pressure on the walls of the concrete body from the water outside the body.

When the concrete body has been fabricated to its desired length, the form can be removed from the upper end of the concrete body and this end of the body can be sealed, e.g. with a concrete. bulkhead, whereafter the water present within the concrete body can be drawn therefrom completely or partially, until the concrete body is floating in the water with its longitudinal axis substantially horizontal. In this position the concrete body can be towed to the place where it is to be used. With the method according to the invention the concrete body can consequently be fabricated at one place, where the water depth and other conditions are more suitable than at the place, where the concrete body is to be used.

When the concrete. body shall have open ends when it is used, e.g. for tunnel sections, the first fabricated end section for the concrete body is preferably removable so that it can be removed from the concrete body, when this has been fabricated to its desired length, and reused for the fabrication of further concrete bodies.

Other objects and further novel features of the present invention will become more fully apparent from the following detailed description in conjunction with the accompanying drawing, in which FIGS. 1 to 4 are elevation views in section of four different stages of the fabrication of an elongated, cylindrical, hollow concrete body by the method according to the invention.

In the drawing FIG. 1 shows the first fabricated, closed bottom section 1 of the hollow concrete body to be fabricated. This bottom section is preferably fabricated on land and may consist of reinforced concrete for forming an integral part of the concrete body to be fabricated. Alternatively this bottom or end section may be constructed of steel or any other suitable material and be removable from the fabricated concrete body, when'this is completed, and reusable for the fabrication of further concrete bodies. The bottom section 1 is placed float- 7 ing with its open end facing upwards on the surface of a free body of water 2, preferably having a depth exceeding the desired length of the concrete body to be fabricated. On the upper edge of this bottom section 1 a suitable form for the pouring of concrete, preferably a slip-form, is placed. The form 3 is preferably substantially entirely supported from the floating bottom section 1. Lateral movement of the bottom section 1 .is prevented by means of pontoons, floats, tanks or similar equipment 4-, which also can serve as a platform for the pouring of concrete into the :form 3. A certain amount of water 5 is filled into the bottom section 1 from the beginning of the operation so that the upper edge of they form 3 assumes a suitable position above the surface of the surrounding water v2. Thereafter concrete is poured in the form 3 and the form is progressively raised as the poured concrete sets, in conventional manner. Simultaneously more water is filled into the already fabricated portion of the concrete body so that this sinks vertically downwards in the surrounding water while remaining substantially independently floating therein with the upper edge of the form 3 at the desired height above the surface of the surrounding water, as shown in FIGS. 2 and 3, and with the entire weight of the bottom sec tion 1 and the already fabricated portion of the concrete body balanced by the upward thrust from the surrounding water 2. When the concrete body has reached its desired length, the form 3 is removed, and the upper end of the concrete body may besealed by means of a bulkhead as shown in FIG. 4. Thereafter the water 5 present in the concrete body can be drawn therefrom completely or partially so that the concrete body assumes a floating position in the waterwith its longitudinal axis horizontal.- In this position the concrete body can be easily towed to the place, where it is to be used.

Although the method according to the invention is particularly advantageous for the fabrication of hollow elongated concrete bodies, which are to be used in water, it is evident that the method can also be used for making elongated hollow concrete bodies, which are to be .used on land: In this case the concrete body must, however, when its fabrication has been completed in the manner described above, be hauled up on land e.g. on a slipway.

I claim:

1. .A method of making an elongated hollow concrete body, comprising fabricating a comparatively short end section having a closed end and an opposite open end; floatingrsaid end section on the surface ofa body of water with said openend facing upwards at a level above the surface of said water, said end section having an-upper edge at said open end which lies above the surface of the wa'teryresting a form for the pouring of concrete with its entire weight at the upper edge of said end section; and progressively fabricating the concrete body on top of the upper edge of the end section in vertically upwards direction by pouring concrete in said form while maintaining the body in floating relation in the water, and progressively lowering said end section and the fabricated portion of said concrete body relative to said form in concurrence with the fabrication of the concrete body by simultaneously filling water into'said end section and the fabricated portion of the concrete body so that said end section and the fabricated portion of said concrete body sink together vertically downwards in the surrounding water while independently floating therein with the upper edge of said fabricated portion together with said form-disposed above the. surface of the surrounding water, the entire weight of said end section, the fabricated portion of said concrete body, and the form being balanced by the upward thrust from the surrounding water. i

2. A method as claimed in claim 1, wherein the form for the pouring of concrete is a slip-form.

3. A method as claimed in claim 1 comprising removing the end section from the concrete body, when said concrete body has been fabricated to a desired length.

4. A method as claimed in'claim 1, wherein said end section is made an integralpart of said concrete body.

5. Amethod of fabricating an elongated hollow-concrete body comprising successively pouring concrete onto a closed bottom section which is floating in a body of water to form a vertical hollow assembly which floats in the water and successively loweringthe floating assembly in the Water by partially filling the same with a fluid to enable the successive pouring of concrete to be effected at constant level.

6. A method of fabricating an elongated hollow con crete body comprising erecting a concrete vertical body in a body of water by successively pouring concrete at water level in the form of an annular body onto a closed bottom section to form a composite assembly whichfloats in the water and successively adding water in prescribed amount 2,045,789 6/ 1936 McDowell 2513l .into the interior of said assembly after each successive 2,887,759 5/1959 Brownell 50531 pouring of the concrete to cause the floating assembly to 2,972,234 2/ 1961 Suderow 6152 sink to a lower level in the body of water whereby the 3,097,493 7/1963 Blankevoort 6146 XR successive pouring of the concrete for lengthening the 5 body can be effected at substantially a constant level and FOREIGN PATENTS the lengthened body remains floating in the body of water. 694,259 12/1930 France- References Cited by the Examiner ROBERT WHITE, Primary Examiner- UNITED STATES PATENTS 10 ALEXANDER H. BRODMERKEL, Examiner 1,758,606. 5/1930 Jacobs 6146 J. A. FINLAYSON, Assistant Examiner. 

1. A METHOD OF MAKING AN ELONGATED HOLLOW CONCRETE BODY, COMPRISING FABRICATING A COMPARATIVELY SHORE END SECTION HAVING A CLOSED END AND AN OPPOSITE OPEN END; FLOATING SAID END SECTION ON THE SURFACE OF A BODY OF WATER WITH SAID OPEN END FACING UPWARDS AT A LEVEL ABOVE THE SURFACE OF SAID WATER, SAID END SECTION HAVING AN UPPER EDGE AT SAID OPEN END WHICH LIES ABOVE THE SURFACE OF THE WATER; RESTING A FORM FOR THE POURING OF CONCRETE WITH ITS ENTIRE WEIGHT AT THE UPPER EDGE OF SAID END SECTION; AND PROGRESSIVELY FABRICATING THE CONCRETE BODY ON TOP OF THE UPPER EDGE OF THE END SECTION IN VERTICALLY UPWARDS DIRECTION BY POURING CONCRETE IN SAID FORM WHILE MAINTAINING THE BODY IN FLOATING RELATION IN THE WATER, AND PROGRESSIVELY LOWERING SAID END SECTION AND THE FABRICATED PORTION OF 